Two experiments have been completed studying the effect of dietary Na2-EDTA and ascorbic acid at 4 levels (0 to 37.1 x 10 to the minus 3rd power moles/kg of diet) on growing chickens fed 0.2, 0.5 or 1.0% calcium in the diet. Ascorbic acid had no effect on weight gain but Na2-EDTA depressed growth at low levels of calcium. Both chelating agents improved slightly the deposition of calcium in the tibia. No effect of the chelating agents on calcium metabolism was noted at the higher levels of Ca. A long term experiment is in progress studying the effect of dietary ascorbic acid on calcium utilization in adult male chickens in which the calcium requirement closely approximates that of adult humans. Adult coturnix will also be tested for their suitability for use in studies of this type.